[PATCH 10/32] GFS2: Clean up fsync()

From: Steven Whitehouse
Date: Thu May 19 2011 - 05:16:25 EST


This patch is designed to clean up GFS2's fsync
implementation and ensure that it really does get everything on
disk. Since ->write_inode() has been updated, we can call that
via the vfs library function sync_inode_metadata() and the only
remaining thing that has to be done is to ensure that we get
any revoke records in the log after the inode has been written back.

Signed-off-by: Steven Whitehouse <swhiteho@xxxxxxxxxx>

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index e483108..23eab47 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -545,18 +545,10 @@ static int gfs2_close(struct inode *inode, struct file *file)
/**
* gfs2_fsync - sync the dirty data for a file (across the cluster)
* @file: the file that points to the dentry (we ignore this)
- * @dentry: the dentry that points to the inode to sync
+ * @datasync: set if we can ignore timestamp changes
*
- * The VFS will flush "normal" data for us. We only need to worry
- * about metadata here. For journaled data, we just do a log flush
- * as we can't avoid it. Otherwise we can just bale out if datasync
- * is set. For stuffed inodes we must flush the log in order to
- * ensure that all data is on disk.
- *
- * The call to write_inode_now() is there to write back metadata and
- * the inode itself. It does also try and write the data, but thats
- * (hopefully) a no-op due to the VFS having already called filemap_fdatawrite()
- * for us.
+ * The VFS will flush data for us. We only need to worry
+ * about metadata here.
*
* Returns: errno
*/
@@ -565,22 +557,20 @@ static int gfs2_fsync(struct file *file, int datasync)
{
struct inode *inode = file->f_mapping->host;
int sync_state = inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC);
- int ret = 0;
-
- if (gfs2_is_jdata(GFS2_I(inode))) {
- gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);
- return 0;
- }
+ struct gfs2_inode *ip = GFS2_I(inode);
+ int ret;

- if (sync_state != 0) {
- if (!datasync)
- ret = write_inode_now(inode, 0);
+ if (datasync)
+ sync_state &= ~I_DIRTY_SYNC;

- if (gfs2_is_stuffed(GFS2_I(inode)))
- gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);
+ if (sync_state) {
+ ret = sync_inode_metadata(inode, 1);
+ if (ret)
+ return ret;
+ gfs2_ail_flush(ip->i_gl);
}

- return ret;
+ return 0;
}

/**
diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index 25eeb2b..7c1b08f 100644
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -28,33 +28,18 @@
#include "trans.h"

/**
- * ail_empty_gl - remove all buffers for a given lock from the AIL
+ * __gfs2_ail_flush - remove all buffers for a given lock from the AIL
* @gl: the glock
*
* None of the buffers should be dirty, locked, or pinned.
*/

-static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
+static void __gfs2_ail_flush(struct gfs2_glock *gl)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
struct list_head *head = &gl->gl_ail_list;
struct gfs2_bufdata *bd;
struct buffer_head *bh;
- struct gfs2_trans tr;
-
- memset(&tr, 0, sizeof(tr));
- tr.tr_revokes = atomic_read(&gl->gl_ail_count);
-
- if (!tr.tr_revokes)
- return;
-
- /* A shortened, inline version of gfs2_trans_begin() */
- tr.tr_reserved = 1 + gfs2_struct2blk(sdp, tr.tr_revokes, sizeof(u64));
- tr.tr_ip = (unsigned long)__builtin_return_address(0);
- INIT_LIST_HEAD(&tr.tr_list_buf);
- gfs2_log_reserve(sdp, tr.tr_reserved);
- BUG_ON(current->journal_info);
- current->journal_info = &tr;

spin_lock(&sdp->sd_ail_lock);
while (!list_empty(head)) {
@@ -76,7 +61,47 @@ static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
}
gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
spin_unlock(&sdp->sd_ail_lock);
+}
+
+
+static void gfs2_ail_empty_gl(struct gfs2_glock *gl)
+{
+ struct gfs2_sbd *sdp = gl->gl_sbd;
+ struct gfs2_trans tr;
+
+ memset(&tr, 0, sizeof(tr));
+ tr.tr_revokes = atomic_read(&gl->gl_ail_count);
+
+ if (!tr.tr_revokes)
+ return;
+
+ /* A shortened, inline version of gfs2_trans_begin() */
+ tr.tr_reserved = 1 + gfs2_struct2blk(sdp, tr.tr_revokes, sizeof(u64));
+ tr.tr_ip = (unsigned long)__builtin_return_address(0);
+ INIT_LIST_HEAD(&tr.tr_list_buf);
+ gfs2_log_reserve(sdp, tr.tr_reserved);
+ BUG_ON(current->journal_info);
+ current->journal_info = &tr;
+
+ __gfs2_ail_flush(gl);
+
+ gfs2_trans_end(sdp);
+ gfs2_log_flush(sdp, NULL);
+}

+void gfs2_ail_flush(struct gfs2_glock *gl)
+{
+ struct gfs2_sbd *sdp = gl->gl_sbd;
+ unsigned int revokes = atomic_read(&gl->gl_ail_count);
+ int ret;
+
+ if (!revokes)
+ return;
+
+ ret = gfs2_trans_begin(sdp, 0, revokes);
+ if (ret)
+ return;
+ __gfs2_ail_flush(gl);
gfs2_trans_end(sdp);
gfs2_log_flush(sdp, NULL);
}
diff --git a/fs/gfs2/glops.h b/fs/gfs2/glops.h
index b3aa2e3..6fce409 100644
--- a/fs/gfs2/glops.h
+++ b/fs/gfs2/glops.h
@@ -23,4 +23,6 @@ extern const struct gfs2_glock_operations gfs2_quota_glops;
extern const struct gfs2_glock_operations gfs2_journal_glops;
extern const struct gfs2_glock_operations *gfs2_glops_list[];

+extern void gfs2_ail_flush(struct gfs2_glock *gl);
+
#endif /* __GLOPS_DOT_H__ */
--
1.7.4

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